Clamping device, sensor module, and sensor assembly

Abstract

An alternative clamping device for clamping a part and a sensor module for such a clamping device are provided, in which the drawbacks of the prior art are avoided. SOLUTION: A clamping device (1) for clamping a workpiece, in particular for fastening a tool to a machine tool, comprising a body (2) defining a clamping axis (X), in which a clamping area (3) for a workpiece to be clamped, in particular for a tool shaft, is arranged in a front end area of ​​the body, and a sensor module (10) formed as a structural unit, the sensor module (10) being inserted into an accommodation space (9) and held there.

Description

Technical Field

[0001] The present invention relates to a clamping device for clamping a component, particularly for fixing a tool to a machine tool, comprising a body defining a clamping shaft, wherein a clamping area for the component to be clamped, particularly for a tool shaft, is arranged in the front end area of the body. The present invention further relates to a sensor module and a sensor assembly, particularly for such a clamping device.

Background Art

[0002] For example, such clamping devices for fixing tools to machine tools are known in various forms and are used, for example, to fix tools such as milling tools or drill tools for machining workpieces to the working spindle of a machine tool. Such a clamping device typically comprises a body defining a clamping shaft and a clamping area in the front end area where the component to be clamped is held in a force-locking manner. In that case, the clamping device can be formed as a chuck, which means that the clamping area has, for example, a receiving part for a tool shaft. Alternatively, the clamping device can also be formed as a clamping mandrel. In this case, the clamping area comprises a clamping surface pointing radially outwards for fixing the component in a force-locking manner from the inside.

[0003] In order to enable the detection of various operating parameters during the machining process, it is increasingly common to equip such clamping devices with sensors. For example, such a clamping device can have an acceleration sensor for detecting vibrations during the machining process. Such vibrations can occur when the tool for the machining inserted into the clamping device is worn.

[0004] A temperature sensor may be provided to detect, in some cases, insufficient cooling of the inserted tool. Furthermore, the appropriate sensor can determine the deformation of the main body, and the resulting cutting force can be inferred from there. The data detected by such sensors can be transmitted to the central machine control unit via an appropriate transmission device, and in some cases, the machining parameters can be adjusted.

[0005] Such clamping devices formed as tool holders are known from Patent Document 1. These clamping devices are used to secure a tool to the working spindle of a machine tool and comprise a body that defines a clamping axis. A clamping region is formed in the front end region of the body, having a central housing for the shaft of the tool to be clamped, which opens toward the front end face of the body. Sensors are located at several points on the body. These sensors are also connected via electrical wiring to outwardly open recesses for housing signal transmission devices. Energy supply devices connected to the sensors via electrical wiring may also be provided at other locations on the body.

[0006] While the capabilities of such tool holders are generally proven, the cumbersome process of changing sensors is considered a partial disadvantage. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] German Patent Application Publication No. 102015220533 Specification [Overview of the project] [Problems that the invention aims to solve]

[0008] Therefore, the object of the present invention is to provide an alternative clamping device for clamping parts, and a sensor module for such a clamping device, in particular, which avoids the above-mentioned drawbacks. [Means for solving the problem]

[0009] The above problem is solved in the clamp device of the type described at the beginning, by forming a housing space for a sensor module in the main body, and this housing space opening toward the circumferential surface of the main body and extending radially into the main body from this circumferential surface. Furthermore, according to the present invention, the clamp device comprises a sensor module, the sensor module is formed as a structural unit, and has a tubular sensor housing that defines the sensor axis, a closing cap that tightly closes the end face of the sensor housing, a sensor element housed in the sensor housing for detecting operating parameters, and a data transmission device connected to the sensor element for wirelessly transmitting measurement data detected by the sensor element to a receiver located outside the clamp device, and the sensor module is intended to be inserted into the housing space with the closing cap pointing outwards and held in the housing space.

[0010] Furthermore, the fundamental problem of the present invention is solved by a sensor module for such a clamping device, which is formed as a structural unit and comprises a tubular sensor housing that defines a sensor axis, a closing cap that tightly closes the sensor housing at its end face, a sensor element housed within the sensor housing for detecting measurement data, and a data transmission device connected to the sensor element for wirelessly transmitting the measurement data detected by the sensor element to a receiver located outside the clamping device.

[0011] The present invention is based on the fundamental idea of ​​providing an outwardly opening closing cap on a sensor module formed as a structural unit and inserted into the housing space of a clamp device. This allows functional components that should be accessible from the outside to be provided on the closing cap. At the same time, other components such as sensor elements or energy supply devices can be protected and housed inside the housing space. Furthermore, such a sensor module as a structural unit can be replaced quickly and easily without the need to remove individual sensors.

[0012] Specifically, the sensor element may include a temperature sensor and / or motion sensor, in particular a sensor for detecting the rotational speed of the clamping device, and / or a pressure sensor, and / or a deformation sensor and / or an acceleration sensor. Basically, the sensor element may include one or more sensors. When the clamping device according to the present invention is used to fix a tool to a machine tool, for example, the cutting speed can be detected indirectly via the rotational speed sensor. Furthermore, a sensor element including an acceleration sensor can detect vibrations that occur. A temperature sensor makes it possible to recognize excessively high temperatures of the body. In particular, if the sensor element is located near the cooling medium line, the cooling medium temperature can be detected relatively accurately by the temperature sensor.

[0013] According to a preferred embodiment of the present invention, the data transmission device is incorporated into the closing cap. Direct external access to the data transmission device minimizes signal attenuation, thereby allowing easy transmission of measurement data to a receiver located outside the clamping device. Wireless transmission significantly reduces susceptibility to interference compared to contact transmission, for example, via sliding contacts. In this case, data transmission can be directed particularly towards the machine control unit, enabling control of critical operating parameters. If the sensor element detects vibrations caused by wear of a tool inserted into the clamping device, for example, operating parameters such as rotational speed and / or feed rate can still be adjusted to ensure qualitatively high-value workpiece machining. In this case, the data transmission device is particularly suitable for use in wireless networks and / or for connection to the internet.

[0014] A data transmission device may have an antenna that includes an earth pole and an antenna pole, particularly one that is insert-molded into a closure cap. In this case, the closure cap can be made substantially of plastic, thereby slightly attenuating the signal emitted from the antenna. The antenna is used to radiate electromagnetic waves for wireless transmission of signals. For this purpose, a varying voltage is applied between the earth pole and the antenna pole.

[0015] In another embodiment, the grounding electrode may be or can be conductively connected to the sensor housing. This embodiment is based on the idea that the sensor housing and, in particular, the body of the clamping device are kept at ground potential, and that a potential that changes relative to this ground potential is applied to the antenna electrode in order to emit a signal. In particular, there may be no conductive connection between the grounding electrode and the antenna electrode as needed. Preferably, the grounding electrode is conductively connected to the sensor housing for the frequency range used to transmit measurement data.

[0016] In specific embodiments, a circular, disc-shaped ground and antenna pole can be formed on the closing cap, with the two poles extending particularly parallel to each other, preferably perpendicular to the sensor axis. In other words, two metal discs spaced apart from each other in the direction of the sensor axis can be formed on the closing cap, with these metal discs forming the ground and antenna poles. Such a disc-shaped configuration allows signals to be emitted outward.

[0017] In another embodiment of this design, the antenna pole can be positioned adjacent to the end face of the closing cap pointing outwards, and the ground pole can be located inward relative to the antenna pole in the closing cap, particularly in the area of ​​the ring-shaped outer flange surrounding the closing cap. Positioning the antenna pole near the end face of the closing cap pointing outwards allows for good signal transmission because the material thickness between the antenna pole and the surrounding environment is kept very small, thereby causing only slight signal attenuation. In contrast, it is preferable that the ground pole be attached to the inner end portion of the closing cap.

[0018] To enable the emission of a suitable signal, the antenna pole is preferably connected from the antenna pole to a conductor leading to the interior of the sensor housing, particularly to a substrate. Correspondingly, the ground pole is intended to have a through-hole through which a conductor can pass, electrically insulated from the ground pole. This embodiment is based on the need that a suitable signal, i.e., a suitable voltage, is generated inside the sensor housing, for example on a substrate, and that the antenna pole must be electrically connected to it. Correspondingly, the ground pole is intended to have a through-hole through which such a conductor can pass to the antenna pole.

[0019] In another embodiment, the antenna pole and / or ground pole may have honeycomb-shaped openings, which are filled with a material, particularly plastic. In the clamping device according to the present invention, the closing cap, and consequently the antenna pole and ground pole, are positioned outside the clamping shaft, thereby subjecting them to significant centrifugal force. Accordingly, honeycomb-shaped openings are provided to increase the strength of the two components in the closing cap, and these openings are filled with a material. In particular, the closing cap can be manufactured by insert molding the antenna pole and ground pole. In this case, the openings are filled with a material, thereby firmly fixing the poles to the closing cap and providing resistance to centrifugal force.

[0020] In another embodiment, the clamping device may further include an energy supply unit to supply current to the sensor module. In this case, the energy supply unit is preferably housed in a housing space as a separate component. Specifically, the energy supply unit may be positioned at the inner end of the housing space, thereby being held within the housing space by the sensor module. A shim may be provided between the energy supply unit and the sensor module to position the sensor element on the clamp axis.

[0021] This embodiment is based on the idea of ​​providing an energy supply unit directly adjacent to the sensor module. This may be a battery cell, preferably a rechargeable battery cell. Such a battery cell may be formed as, for example, a lithium-ion battery. Such an energy source is necessary to supply electrical energy to the sensor element either by a machine tool or by another external energy supply unit. In this case, the use of a rechargeable battery cell has the advantage that it does not need to be replaced and can be repeatedly charged, especially when the clamping device is not in use. Shims can be used to ensure that the sensor element is precisely positioned on the clamping axis.

[0022] To charge the energy supply unit, the sensor module may have two externally accessible charging contacts, each electrically connected or connectable to a corresponding contact on the energy supply unit, and electrically isolated from each other, allowing voltage and / or current to be supplied to and charged the energy supply unit by bringing the two charging contacts into contact with the poles of a charging device. In other words, it is intended that externally accessible contacts be provided corresponding to areas of the sensor module, so that the energy supply unit can be charged from the outside via the sensor module by a charging device without the need to remove the sensor module and / or the energy supply unit from its housing space.

[0023] In a specific embodiment, the first charging contact, especially for abutting against the negative pole of the charging device, is preferably arranged at the center of the closing cap. The second charging contact, especially for abutting against the positive pole of the charging device, can be formed by the end face of the sensor housing accessible from the outside. In other words, the charging contact of the closing cap is electrically insulated from the sensor housing, so that one pole of the charging device can be abutted against the closing cap, and the other pole located outside with respect to the sensor axis can be abutted against the front end face of the sensor housing. In that case, the two charging contacts can be arranged axially offset from each other with respect to the sensor axis. In particular, the charging contact arranged on the closing cap can protrude towards the end face of the sensor housing.

[0024] The first charging contact can be conductively connected to the antenna pole, especially by a contact area formed on the antenna pole and open to the outside. In other words, it can be contemplated that the antenna pole itself simultaneously forms the first charging contact. Specifically, this first charging contact can extend over a partial area of the antenna pole, especially formed at the center of the antenna pole. In this partial area, a corresponding raised portion that is open to the outside, i.e., not covered by the electrically insulating material of the closing cap, can be formed. Similarly, in the area of the first charging contact, a cover (such as an electrically insulating layer) can be omitted, so that direct access to the antenna pole from the outside can be achieved.

[0025] Preferably, the sensor housing is connected to a corresponding electrical contact of the energy supply unit, and the closing cap is connected to another electrical contact of the energy supply unit. For example, the energy supply unit may be formed in a disc shape and have an outer contact ring that contacts the sensor housing directly or via a shim, and an inner circular contact surface that is electrically connected to a charging contact of the closing cap, in particular, on the end face pointing to the sensor module. Accordingly, the sensor module according to the present invention is characterized in that a data transmission device is incorporated into the closing cap, and / or the sensor module has two charging contacts accessible from the outside, each of which is electrically connectable to a corresponding contact of the energy supply unit and electrically insulated from one another, and that voltage and / or current can be supplied to and charged the energy supply unit by bringing the charging contacts into contact with a charging device, preferably a first charging contact for contacting the negative terminal of the charging device is located on the closing cap, preferably in the center of the closing cap, and a second charging contact for contacting the positive terminal of the charging device is formed by the end face of the sensor housing on the closing cap side.

[0026] In a preferred embodiment of the clamping device according to the present invention, the accommodation space is intended to intersect the clamp axis but not to completely penetrate the body radially. In other words, the accommodation space extends from the radial circumferential surface beyond the clamp axis and terminates in the radial region of the body located on the opposite side of the open end. In this case, the accommodation space may have a circular cross-section, and in particular may be formed in a stepped manner, i.e., it may have regions of various diameters.

[0027] Preferably, the sensor element is arranged in the sensor housing so as to be located on the clamping axis or to be arranged on the clamping axis of the clamping device. This embodiment is based on the idea that no centrifugal force acts on such a sensor element centered with respect to the clamping axis, which improves the function and / or lifespan of the sensor element.

[0028] In another embodiment, the sensor module can have a substrate arranged in the sensor housing and supporting the sensor element. The substrate preferably extends parallel to the sensor axis and includes data processing means for processing the measurement signal provided by the sensor element. In that case, the substrate with the electronic components can be easily pre-manufactured, thereby having the advantage of being easily assembled into the sensor housing. The data processing means may be designed, for example, such that the measurement signal provided by the sensor element is processed and provided to the data transmission unit in a processed form. For example, a temperature sensor formed as a thermocouple can provide a small voltage as a measurement signal, which is then correspondingly converted by the data processing means into a signal that can be transmitted.

[0029] The main body may have at least one cooling medium channel to deliver the cooling medium forward from the mechanical interface on the back of the main body toward the clamp area. In this case, preferably at least one cooling medium channel formed as a central axial through-hole may intersect with the housing space, thereby dividing the cooling medium channel into a front channel portion and a rear channel portion. Accordingly, a ring-shaped cooling medium groove may be formed on the outer circumferential surface of the sensor housing, thereby allowing the cooling medium to be delivered to the clamp area to flow through the cooling medium groove from the rear channel portion to the front channel portion through the sensor housing. This embodiment is based on the idea that, especially when the cooling medium channel is centrally positioned, the housing space penetrates this cooling medium channel, thereby essentially obstructing the flow of the cooling medium by the inserted sensor element. Accordingly, a cooling medium groove is provided on the outer wall of the sensor housing, allowing the cooling medium to flow through this groove through the sensor housing. In this case, it is preferable that the width of the cooling medium groove is adjusted to match the diameter or flow path cross-section of at least one cooling medium channel in order to enable unobstructed flow. In particular, the width of the cooling medium groove may correspond to the diameter of the associated cooling medium channel.

[0030] Appropriate sealing means can be provided to seal the gap between the sensor housing and the wall of the housing space on both sides of the cooling medium groove. Specifically, ring-shaped sealing grooves can be formed around the cooling medium groove in the sensor housing, and a sealing ring can be inserted into or be inserted into these sealing grooves and pressed against the wall of the housing space. This prevents the cooling medium from flowing out through the gap between the sensor housing and the wall of the housing space.

[0031] In a preferred embodiment, the sensor module is screwed into the main body, and in particular, a male thread is formed in the sensor housing, which is screwed into a corresponding female thread in the housing space.

[0032] To allow the sensor module to be easily screwed into the housing space, a corresponding engagement means for the tool can be formed. This engagement means may include a plurality, particularly three, recesses distributed circumferentially and opening toward a closed end face and radially outward with respect to the sensor axis, with these recesses preferably extending into the male thread. Correspondingly, the tool may have corresponding protrusions that engage with the recesses, thereby transmitting the rotational motion of the tool to the sensor module. If these are three recesses distributed circumferentially, the tool is simultaneously centered relative to the sensor module.

[0033] In another embodiment, a ring-shaped flange projecting radially inward may be provided on the closed end region of the sensor housing, which engages from the rear with a corresponding ring-shaped outer flange of the closing cap, thereby morphologically holding the closing cap to the sensor housing. For sealing, the closing cap may also be bonded, soldered, welded, or crimped to the sensor housing, either additionally or as an alternative.

[0034] In another embodiment, the body of the clamping device according to the present invention may have a mechanical interface in its axial rear end region, including a mounting contour and a ring flange. Such a mechanical interface may be formed, for example, as a hollow shank (HSK) and standardized by DIN 69893-1. Alternatively, the body may include a steep taper (SK) according to DIN 2080 as the mechanical interface.

[0035] Preferably, the housing space for the sensor element is located in the body portion that is positioned axially in front of the mechanical interface. This allows for easy access to any receiving equipment that may be present for signals transmitted from the data transmission device.

[0036] The clamping device according to the present invention can be formed as a heat-shrink chuck. In this case, the clamping area includes a housing, which is usually formed as a hole, the diameter of which is slightly smaller than the outer shape of the part to be clamped. When a part is to be introduced into the housing, the body is heated, and the diameter of the housing expands due to the resulting thermal expansion. The part can then be inserted into the housing with some play, and the part is then clamped forcefully as the body cools. Such a heat-shrink chuck may suffer wear if parts are repeatedly clamped, which can lead to vibration. In this case, for example, a sensor element can be used to detect this vibration and thus wear early, thereby enabling timely replacement of the clamping device or modification of its operating parameters.

[0037] Alternatively, the clamping device can be formed as a hydrodehn-spannfutter, where the housing for the part is surrounded in a ring shape by a pressure chamber loadable with a hydraulic medium, and a thin wall is provided between the housing and the pressure chamber, which is elastically deformable inward as the pressure in the pressure chamber increases, thereby forcefully securing the tool shaft inserted into the housing. In such a hydrodehn-spannfutter, the housing is usually formed as a hole, in which case the diameter of the hole is slightly larger than the diameter of the part to be clamped, thereby allowing the part to be inserted into the housing hole without issue. To clamp, pressure is applied to the hydraulic medium in the pressure chamber by appropriate clamping means, thereby deforming the wall of the housing hole radially inward and forcefully securing the part inserted into the housing hole.

[0038] The problems that form the basis of the present invention are further solved by a sensor assembly for mounting on a component, particularly on a tool holder, or on a tool, preferably on a turning tool, comprising: a base having mounting means for mounting on a component and having a housing space formed therein for a sensor module that opens toward the outer surface of the base; and a sensor module according to the present invention inserted into the housing space and particularly screwed in.

[0039] This embodiment is based on the idea of ​​retrofitting such a sensor assembly to a part, for example, to detect vibrations that occur. Accordingly, the base is provided with mounting means so that the base can be attached to the part. Such a sensor assembly is particularly suitable for attachment to stationary and / or non-rotating tools, such as turning tools or turning tool holders. As tool wear progresses, vibrations may occur during machining, and these vibrations can be detected by a sensor module screwed into a housing space. In that case, the detected data can be transmitted by a data transmission device to an external receiver connected, for example, to a machine control unit, thereby allowing the operating parameters to be adapted accordingly.

[0040] In another embodiment of the sensor assembly according to the present invention, the sensor assembly may further include an energy supply unit for supplying current to the sensor module, the energy supply unit being housed in a housing space, preferably located at the inner end of the housing space.

[0041] The mounting means may include a receiving opening for mounting to a component. For example, the receiving opening may have a circular cross-section, thereby allowing the base to be fitted into a turning tool holder having a corresponding cross-section. The mounting means may further be designed to secure the base to the component. For this purpose, corresponding threaded holes opening into the receiving opening may be provided, for example, to allow the base to be forcefully attached to the component by a plurality of clamping screws.

[0042] For other advantageous embodiments of the present invention, please refer to the dependent claims and the following description of embodiments associated with the accompanying drawings. [Brief explanation of the drawing]

[0043] [Figure 1] This is a perspective view of the clamping device according to the present invention. [Figure 2] Figure 1 is a partial longitudinal cross-sectional view of the clamping device. [Figure 3] This is a partial longitudinal cross-sectional view of the clamping device shown in Figure 1, with magnetic field lines drawn on it. [Figure 4] This is another detailed longitudinal cross-sectional view of the clamping device shown in Figure 1. [Figure 5] Figure 4 shows a diagram with magnetic field lines drawn on it. [Figure 6] Figure 1 is a detailed cross-sectional view of the main body of the clamping device. [Figure 7] This is a perspective view of the sensor module according to the present invention. [Figure 8] Figure 7 is a perspective longitudinal cross-sectional view of the sensor module. [Figure 9] Figure 7 is a longitudinal cross-sectional view of the sensor module. [Figure 10] Figure 7 is a detailed cross-sectional view of the end region on the closing cap side of the sensor module. [Figure 11] Figure 7 is a perspective view of the antenna of the sensor module. [Figure 12] This is a perspective view of the sensor assembly according to the present invention. [Figure 13] Figure 12 is a cross-sectional view of the sensor assembly. [Modes for carrying out the invention]

[0044] Figures 1 to 5 show a clamping device 1 according to the present invention, formed as a chuck for fixing a tool to a machine tool. This clamping device comprises a body 2 that defines a clamping axis X, and a clamping area 3 for the tool shaft is located in the front end region of the body. The clamping area includes a housing 4 into which the tool shaft of the tool to be clamped can be inserted.

[0045] Here, the clamping device 1 is formed as a hydraulic expansion chuck. This means that the housing 4 is slightly larger than the tool shaft to be clamped, thereby allowing some play in the housing 4 to be provided for insertion of the tool shaft. The housing 4 is separated from a ring-shaped, circumferentially arranged pressure chamber 6, which is filled with a hydraulic medium, by a thin wall 5. The thin wall 5 can deform radially inward as the pressure in the pressure chamber 6 increases, thereby forcefully fixing the inserted tool shaft to the housing 4. Specifically, a clamping screw 7 is provided for this purpose, which can move within a hydraulic medium supply channel (not shown) to increase or decrease the pressure in the pressure chamber 6.

[0046] The main body 2 is equipped with a mechanical interface 8 formed as a hollow shank (HSK) according to DIN69893 at its rear end.

[0047] The main body 2 further has a housing space 9 for accommodating the sensor module 10. In Figures 1 to 5, the sensor module 10 is inserted into the housing space 9. In Figure 6, the housing space 9 without the sensor module is shown in detail. The housing space 9 opens toward the circumferential surface of the main body 2 and extends radially into the main body 2 from this circumferential surface. In this case, the housing space 9, which has a circular cross-section, intersects with the clamp axis X but does not completely penetrate the main body 2 radially.

[0048] The main body 2 further has a cooling medium channel 11 formed therein to send the cooling medium forward from the mechanical interface 8 on the back towards the clamp area 3. The cooling medium channel 11 is arranged coaxially with the clamp axis X, so that the housing space 9 intersects with the cooling medium channel 11 and divides it into a front channel portion 12 and a rear channel portion 13.

[0049] Here, the sensor module 10, formed as a structural unit and shown separately in Figures 7 to 9, comprises a tubular sensor housing 14 that defines the sensor axis Y. The sensor housing 14 allows the sensor module 10 to be screwed into the housing space 9 of the main body 2. For this purpose, the housing space 9 has an outward-facing end region with a female thread 15, which opens radially inward into an undercut (Freistich) 16. Accordingly, a male thread 17 corresponding to the sensor housing 14 is provided. Both threads 15 and 17 are formed here as metric fine-pitch threads.

[0050] To allow the sensor module 10 to be screwed into the housing space 9, the sensor housing 14 is formed with a tooling mechanism. The tooling mechanism includes three recesses 18 distributed circumferentially and opening toward the end face and radially outward relative to the sensor axis, these recesses extending into the male thread.

[0051] Since the diameter of the containment space 9 is larger than the diameter of the cooling medium channel 11, a ring-shaped cooling medium groove 19 is formed around the outer surface of the sensor housing 14. In this case, the width of the cooling medium groove 19 substantially corresponds to the diameter of the cooling medium channel 11. As a result, the cooling medium sent toward the clamp area 3 can flow from the rear channel portion 13 through the cooling medium groove 19, through the sensor housing 14, and into the front channel portion 12.

[0052] To seal the gap between the sensor housing 14 of the sensor module 10 and the wall of the housing space 9, ring-shaped sealing grooves 20 and 21 are formed around both sides of the cooling medium groove 19. In particular, as can be seen in Figure 3, a sealing ring 22 is inserted into these sealing grooves and pressed against the wall of the housing space 9.

[0053] To prevent damage to the seal ring 22 when inserting the sensor module 10 into the housing space 9, the housing space 9 is formed in a stepped manner. This means that the region of the housing space 9 extending from the cooling medium channel 11, shown above the clamp axis X in Figure 4, to the open end has a somewhat larger diameter than the region extending from the cooling medium channel 11 to the closed end, which is located below the clamp axis X in Figure 4. Accordingly, the diameter of the bottom of the seal groove 20 is also somewhat larger than the diameter of the bottom of the seal groove 21.

[0054] The sensor module 10 further includes a closing cap 23 that tightly closes the sensor housing 14 at its end face. In Figure 2, it can be seen that the closing cap 23 points to the end that opens outward from the housing space 9. Specifically, the closed end region of the sensor housing 14 is provided with a ring flange 24 that projects radially inward, and this ring flange engages from the rear with a corresponding ring-shaped outer flange portion 25 of the closing cap 23. In this way, the closing cap 23 is held to the sensor housing 14 in a shape-coupled manner.

[0055] Furthermore, the clamping device 1 includes an energy supply unit 26 to supply current to the sensor module 10. The energy supply unit 26, which is formed as a rechargeable battery, is housed here as a separate component in the housing space. Specifically, the energy supply unit 26 is located at the internal end of the housing space 9. A shim 27 is placed between the energy supply unit 26 and the sensor housing 14.

[0056] To enable charging of the energy supply unit 26, the sensor module 10 has two externally accessible charging contacts. A first charging contact 28, specifically for contacting the negative terminal of the charging device, is located on the closing cap 23, in this case, at the center of the closing cap 23. A second charging contact 29, specifically for contacting the positive terminal of the charging device, is formed by a ring-shaped end face of the externally accessible sensor housing 14. This means that a potential difference can be applied between the sensor housing 14 and the first charging contact 28 located on the closing cap 23. In this case, the second charging contact 29 is electrically connected to the corresponding contact of the energy supply unit 26 via the sensor housing 14 and a shim 27. Furthermore, an electrical connection is formed between the first charging contact 28 located on the closing cap 24 and the corresponding contact of the energy supply unit 26. In this way, voltage and / or current can be supplied to the energy supply unit 26 from the outside.

[0057] The sensor module 10 further comprises a substrate 30 positioned within the sensor housing 14 and extending parallel to the sensor axis Y. In this case, the substrate 30 supports a sensor element 31 for detecting operating parameters. The sensor element 31 may include one or more sensors, such as an acceleration sensor and / or a temperature sensor and / or a motion sensor and / or a pressure sensor and / or a deformation sensor, for example, to recognize vibrations occurring. To prevent the effects of centrifugal force, the sensor element 31 is positioned within the sensor housing 14 so that it is located on the clamp axis X or is positionable, by the selection of an appropriate shim 27.

[0058] The substrate 30 further includes data processing means for processing measurement signals provided by the sensor element 31, and is further connected to a data transmission device 32 for wirelessly transmitting the measurement data detected by the sensor element 31 to a receiver located outside the clamping device 1. Here, the data transmission device 32 incorporates a closing cap 23, which enables external transmission with minimal interference.

[0059] Specifically, the data transmission device 32 includes an antenna 33 insert-molded into the closing cap 23. This antenna has a disc-shaped ground electrode 34 located in the region of the ring-shaped outer flange 25 and electrically connected to the sensor housing 14, and a disc-shaped antenna electrode 35 positioned adjacent to the end face of the closing cap 23 pointing outwards. The ground electrode 34 and the antenna electrode 35 are shown as dashed lines in the cross-sectional view, respectively. As can be seen particularly in Figure 10, the diameter of the disc-shaped ground electrode 34 is slightly larger than the diameter of the closing cap 23 at its outer end, and therefore larger than the diameter of the antenna electrode 35. Preferably, the diameter of the ground electrode 34 is intended to be at least 80%, particularly at least 90%, and especially preferably at least 95%, of the diameter of the outer end region of the closing cap.

[0060] Both the antenna pole 35 and the ground pole 34 are provided with multiple honeycomb-shaped openings 36, which are filled with plastic that substantially forms a closing cap 23. In this way, the ground pole 34 and the antenna pole 35 are particularly advantageously fixed to the closing cap 23, thereby enabling these poles to withstand high mechanical loads due to centrifugal force.

[0061] To apply a potential to the antenna pole 35, the antenna pole 35 is connected to a conductor 37, which extends from the antenna pole 35 into the sensor housing 14 to the substrate 30, as can be seen in Figure 11. Correspondingly, the ground pole 34 has a through-hole 38, and the conductor 37 extends toward the substrate 30, electrically insulated from the ground pole 34 by this through-hole.

[0062] At the center of the antenna pole 35, a contact area 39 is formed that is accessible from the outside, i.e., not covered with plastic, forming a first charging contact 28.

[0063] During operation, the sensor element 31 continuously provides a measurement signal. The measurement signal is processed by data processing means on the substrate 30 and transmitted continuously or at specific time intervals via a data transmission device 32 formed as an antenna 23 to a receiver located outside the clamping device 1, for example, connected to the control unit of a machine tool.

[0064] The magnetic field lines of the antenna 33, generated by the potential difference applied between the ground pole 34 and the antenna pole 35, are schematically shown, for example, in Figures 3 and 5. In this case, for favorable signal transmission, it is necessary that no metal objects are placed in a specific area of ​​the surrounding environment around the clamp device 1 or the sensor module 10. In Figure 10, the structural space boundary having the basic shape of the cone K is shown by a dashed line, and no metal parts should be placed between these dashed lines, i.e., in the central area of ​​Figure 10. In this case, a specific radial distance B must be maintained from the antenna pole 35 with respect to the sensor axis. This distance must be greater than the dimension A at which the antenna pole 35 is separated from the end face on the closing cap side of the sensor housing 14. Dimension A is preferably at least 30% of the diameter of the antenna 35. In this case, the cone opening angle α must be at least 10%, preferably at least 20%.

[0065] If the sensor module 10 according to the present invention needs to be replaced, the screws can be easily removed from the housing space 9. For this purpose, a suitable tool that engages with the recess 18 is used. After the sensor module 10 is removed, the shim 27 and the energy supply unit 26 can be removed from the housing space without any problems.

[0066] Similarly, the clamping device 1 can be reassembled by inserting the energy supply unit 26 into the closed end of the housing space 9. Subsequently, the shim 27 is inserted, and then the sensor module 10 is screwed into the housing space 9. The sensor module 10, formed as a structural unit, can be easily and quickly replaced. At the same time, easy charging of the energy supply device 26 can be achieved via the closing cap 23. Furthermore, data transmission that is less susceptible to interference is performed via the data transmission device 32 housed in the closing cap 26. In this case, highly sensitive components such as the sensor element 31 or the energy supply unit are protected and housed inside the housing space 9 and within the sensor housing 14.

[0067] Figures 12 and 13 show one embodiment of a sensor assembly according to the present invention. This sensor assembly comprises a base 41, the base having a housing space 9 for a sensor module 10. This housing space 9 opens toward the outer surface of the base 40, and the sensor module 10 is screwed into the housing space 9 as described above. As in the case of the clamp device 1 described above, the sensor assembly 40 also comprises an energy supply unit 26, which is located at the inner end of the housing space 9. A shim 27 is positioned between the energy supply unit 26 and the sensor module 10.

[0068] The sensor assembly 40 further comprises mounting means for attaching it to a component. Specifically, these mounting means include a housing opening 42 through which the base 41 can be fitted to the component. A plurality of screw holes 43 are formed radially toward the housing opening 42, and these screw holes allow the base 41 to be fastened and secured to the component using clamping screws.

[0069] The sensor assembly 40 according to the present invention allows the sensor module 10 to be later attached to a part, for example, a turning tool, in order to reliably detect vibrations that may occur as tool wear progresses. Similar to the clamping device described above, the measurement data detected by the sensor element 31 is processed by appropriate data processing means on the substrate 30 and transmitted outward to a receiver by the data transmission device 32. [Explanation of Symbols]

[0070] 1. Clamping device 2 Main unit 3. Clamping area 4. Storage area 5 thin wall 6. Pressure Chamber 7 Clamp screws 8. Mechanical Interface 9 Containment space 10 Sensor Modules 11 Cooling medium channels 12 Previous channel portion 13 Post-channel portion 14 Sensor Housing 15 Female thread 16 Undercut 17 Male thread 18 recesses 19 Cooling medium groove 20 seal grooves 21 Seal groove 22 sealing rings 23 Closing cap 24 Ring flange 25 Outer brim 26 Energy supply units 27 Sims 28. First charging contact 29. Second charging contact 30 circuit boards 31 Sensor element 32 Data transmission devices 33 Antennas 34. Grounding pole 35 Antenna poles 36 Honeycomb-shaped openings 37 Conductors 38 Through-opening 39 Contact Area 40 Sensor Assembly 41 Base 42. Enclosure opening 43 Threaded through-hole B distance A Dimension X clamp axis Y sensor axis K Taper

Claims

1. A clamping device (1) for clamping parts, particularly for fixing tools to machine tools, The clamp comprises a body (2) that defines a clamp axis (X), and a clamping area (3) for the part to be clamped, in particular for a tool shaft, is located in the front end area of ​​the body. The main body (2) has a housing space (9) for the sensor module (10), the housing space opens toward the circumferential surface of the main body (2), and extends radially from the circumferential surface into the main body (2), The system further comprises a sensor module (10), the sensor module being formed as a structural unit, and A tubular sensor housing (14) that defines the sensor axis (Y), A closing cap (23) that tightly closes the end face of the sensor housing (14), A sensor element (31) for detecting operating parameters, housed within the sensor housing (14), wherein the sensor element (31) is positioned within the sensor housing (14) so ​​as to be located on the clamp axis (X), The device includes a data transmission device (32) connected to the sensor element (31) for wirelessly transmitting measurement data detected by the sensor element (31) to a receiver located outside the clamp device (1), The sensor module (10) is inserted into the housing space (9) such that the closing cap (23) faces outwards. The aforementioned containment space is held, Clamping device.

2. The clamping device (1) according to claim 1, characterized in that the data transmission device (32) is incorporated into the closing cap (23).

3. The clamp device (1) according to claim 2, characterized in that the data transmission device (32) has an antenna (33) including a ground pole (34) and an antenna pole (35) which is insert-molded into the closing cap.

4. The clamp device (1) according to claim 3, characterized in that the ground electrode (34) is electrically connected to or can be electrically connected to the sensor housing (14).

5. The clamp device (1) according to claim 3 or 4, characterized in that the grounding electrode (34) and the antenna electrode (35), which are in the shape of a circular disc, are formed on the closing cap (23), and the two electrodes (34, 35) extend particularly parallel to each other, preferably perpendicular to the sensor axis (Y).

6. The clamp device (1) according to claim 5, characterized in that the antenna pole (35) is positioned adjacent to the end face of the closing cap (23) that points to the outside, and the ground pole (34) is positioned inward relative to the antenna pole (35) on the closing cap (23), and in particular in the region of the ring-shaped outer flange portion (25) of the closing cap.

7. The clamp device (1) according to claim 6, characterized in that the antenna pole is connected from the antenna pole to a conductor leading to the inside of the sensor housing, particularly to a substrate, and the ground pole has a through-opening through which the conductor passes while being electrically insulated from the ground pole.

8. The clamping device (1) according to claim 5, characterized in that a honeycomb-shaped opening (36) is formed in the antenna pole (35) and / or the ground pole (34), and the honeycomb-shaped opening (36) is filled with a material, particularly plastic.

9. The clamping device (1) according to prior claim 1, further comprising an energy supply unit (26) for supplying current to the sensor module (10).

10. The clamping device (1) according to claim 9, characterized in that the energy supply unit (26) is housed in the housing space (9) as a separate component.

11. The clamping device (1) according to claim 10, characterized in that the energy supply unit (26) is located at the inner end of the housing space (9), and a shim (27) is located between the energy supply unit (26) and the sensor module (10) to position the sensor element (31) on the clamp axis (X).

12. The clamp device (1) according to claim 9, characterized in that the sensor module (10) has two externally accessible charging contacts (28, 29), each of which is electrically connected to or connectable to a corresponding contact of the energy supply unit (26) and electrically insulated from each other, and that the energy supply unit (26) can be supplied with voltage and / or current and charged by bringing the two charging contacts (28, 29) into contact with the poles of a charging device.

13. The clamping device (1) according to claim 12, characterized in that a first charging contact (28) for contacting the negative terminal of a charging device is located on the closing cap (23), preferably in the center of the closing cap (23), and a second charging contact (29) for contacting the positive terminal of a charging device is formed by an end face of the sensor housing (14) that is accessible from the outside.

14. The clamping device (1) according to claim 12 or 13, characterized in that the first charging contact (28) is electrically connected to the antenna pole (35), and is in particular formed by an outwardly open contact region (39) formed on the antenna pole (35).

15. The clamping device (1) according to claim 1, characterized in that the accommodation space (9) intersects with the clamping axis (X), but does not completely penetrate the main body (2) in the radial direction.

16. The clamping device (1) according to claim 1, characterized in that the sensor module (10) is disposed within the sensor housing (14) and has a substrate (30) that supports the sensor element (31), the substrate (30) preferably extends parallel to the sensor axis (Y) and includes data processing means for processing the measurement signal provided by the sensor element (31).

17. The clamping device (1) according to claim 1, characterized in that the main body (2) has at least one cooling medium channel (11) for sending a cooling medium forward from the mechanical interface on the back side of the main body (2) toward the clamping area (3), the at least one cooling medium channel (11) intersects with the housing space (9), thereby the housing space (9) dividing the cooling medium channel (11) into a front channel portion (12) and a rear channel portion (13), and a ring-shaped cooling medium groove (19) is formed around the outer circumferential surface of the sensor housing (14), thereby allowing the cooling medium sent toward the clamping area (3) to flow through the cooling medium groove (19) from the rear channel portion to the front channel portion, passing through the sensor housing (14).

18. The clamp device (1) according to claim 17, characterized in that sealing means are provided to seal the gap between the sensor housing (14) of the sensor module (10) and the wall of the housing space (9) on both sides of the cooling medium groove (19).

19. The clamp device (1) according to claim 18, characterized in that, in the sensor housing (14), ring-shaped seal grooves (20, 21) are formed on both sides of the cooling medium groove (19), a seal ring (22) is inserted into the seal groove and pressed against the wall of the housing space (9).

20. The clamping device (1) according to claim 1, characterized in that the sensor module (10) is screwed into the main body (2), preferably a male thread (17) is formed in the sensor housing (14), and the male thread is screwed into the corresponding female thread (15) of the housing space (9).

21. The clamping device (1) according to claim 20, characterized in that the sensor housing (14) has an engaging means for a tool formed therein so that the sensor module (10) can be screwed into the housing space (9).

22. The clamping device (1) according to claim 21, characterized in that the engaging means includes a plurality of recesses (18) distributed around the circumference and opening toward the closed end face and radially outward with respect to the sensor axis (Y), wherein the recesses preferably extend into a screw.

23. The clamp device (1) according to claim 1, characterized in that a ring flange portion (24) projecting radially inward is provided on the closed end region of the sensor housing (14), the ring flange portion engages from the rear with a corresponding outer flange portion (25) that is circumferentially provided in a ring shape on the closing cap (23), thereby the closing cap (23) is held in a shape-coupled manner to the sensor housing (14).

24. The clamping device (1) according to claim 17, characterized in that the containment space (9) has a circular cross-section, and the diameter of the containment space (9) is preferably larger than the diameter of the at least one cooling medium channel (11).

25. A sensor module (10) for the clamping device (1) according to claim 1, The sensor module (10) is formed as a structural unit, and A tubular sensor housing (14) that defines the sensor axis (Y), A closing cap (23) that tightly closes the end face of the sensor housing (14), A sensor element (31) for detecting measurement data is housed within the sensor housing (14), A data transmission device (32) connected to the sensor element (31) for wirelessly transmitting measurement data detected by the sensor element (31) to a receiver located outside the clamp device (1), In an observation module equipped with, A sensor module characterized in that the data transmission device (32) is incorporated into the closing cap (23), and / or the sensor module (10) has two externally accessible charging contacts (28, 29), each of which is electrically connectable to a corresponding contact of an energy supply unit (26) and at the same time electrically insulated from each other, and that the energy supply unit (26) can be supplied with voltage and / or current and charged by bringing the charging contacts (28, 29) into contact with a charging device, preferably a first charging contact (28) for contacting the negative terminal of the charging device is located in the closing cap (23), preferably in the center of the closing cap (23), and a second charging contact (29) for contacting the positive terminal of the charging device is formed by the closing cap side end face of the sensor housing (14).

26. The sensor module (10) according to claim 25, characterized in that the data transmission device (32) has an antenna (33) including a ground pole (34) and an antenna pole (35), which is incorporated into the closing cap (23) and, in particular, is insert-molded into the closing cap.

27. The sensor module (10) according to claim 26, characterized in that the ground electrode (34) is electrically connected to or can be electrically connected to the sensor housing (14).

28. The sensor module (10) according to claim 26 or 27, characterized in that the ground electrode (34) and the antenna electrode (35), which are in the shape of a circular disc, are formed on the closing cap (23), and the two electrodes (34, 35) extend particularly parallel to each other, preferably perpendicular to the sensor axis (Y).

29. The sensor module (10) according to claim 28, characterized in that the antenna pole (35) is positioned adjacent to the end face of the closing cap (23) that points outwards, and the ground pole (34) is positioned inward relative to the antenna pole (35) on the closing cap (23), and in particular in the region of the ring-shaped outer flange portion (25) of the closing cap (23).

30. The sensor module (10) according to claim 29, characterized in that the antenna pole (35) is connected to a conductor (37) that extends from the antenna pole (35) to the inside of the sensor housing (14), and the ground pole (34) has a through-opening (38) through which the conductor (37) passes while being electrically insulated from the ground pole (34).

31. The sensor module (10) according to 28, characterized in that the antenna pole (35) and / or the ground pole (34) have honeycomb-shaped openings (36) formed therein, and the honeycomb-shaped openings (36) are filled with a material, particularly plastic.

32. The sensor module (10) according to any one of claims 25 to 27, characterized in that the sensor element (31) is arranged within the sensor housing (14) so ​​as to be positioned on the clamp shaft (X) of the clamp device (1).

33. The sensor module (10) according to any one of claims 25 to 27, characterized in that the sensor module (10) is disposed within the sensor housing (14) and has a substrate (30) supporting the sensor element (31), the substrate (30) preferably extends through the sensor axis (Y) and includes data processing means for processing the measurement signal provided by the sensor element (31).

34. The sensor module (10) according to any one of claims 25 to 27, characterized in that a ring-shaped cooling medium groove (19) is formed on the outer circumferential surface of the sensor housing (14).

35. The sensor module (10) according to claim 34, characterized in that ring-shaped seal grooves (20, 21) are formed on both sides of the cooling medium groove (19), and a seal ring (22) can be inserted into the seal grooves.

36. The sensor module (10) according to any one of claims 25 to 27, characterized in that a male thread (17) is formed on the sensor housing (14).

37. The sensor module (10) according to any one of claims 25 to 27, characterized in that the sensor housing (14) has an engaging means for a tool formed therein so that the sensor module (10) can be screwed into the housing space (9) of the clamping device (1).

38. The sensor module (10) according to 37, characterized in that the engaging means includes a plurality of recesses (18) distributed circumferentially and opening toward the closed end face and radially outward with respect to the longitudinal axis, the recesses preferably extending into the male thread (17).

39. The sensor module (10) according to any one of claims 25 to 27, characterized in that the sensor housing (14) is provided with a ring flange portion (24) that protrudes radially inward, the ring flange portion engages with a corresponding outer flange portion (25) of the closing cap (23) from the rear, thereby the closing cap (23) is held in a shape-coupled manner to the sensor housing (14).

40. In a sensor assembly (40) for attachment to a component, particularly to a tool holder, or to a tool, preferably to a turning tool, A base (41) having mounting means for attaching to a component, and having a housing space (9) for a sensor module (10) formed on the outer surface of the base (41), A sensor assembly comprising: a sensor module (10) according to any one of claims 25 to 27, which is inserted into the aforementioned housing space (9) and is particularly screwed in.

41. The sensor assembly (40) according to claim 40, further comprising an energy supply unit (26) for supplying current to the sensor module (10), wherein the energy supply unit (26) is housed in the housing space (9), preferably located at the inner end of the housing space (9).

42. The sensor assembly (40) according to claim 40, characterized in that the mounting means includes a receiving opening (42) for mounting to a component.

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